Aerospace Engineering Commons^™

An Imu-Based Spacecraft Navigation Architecture Using A Robust Multi-Sensor Fault Detection Scheme, Samuel J. Haberberger

Masters Theses

"Redundant sensor networks of inertial measurement units (IMUs) provide inherent robustness and redundancy to a navigation solution obtained by dead reckoning the fused accelerations and angular velocities sensed by the IMU. However, IMUs have been known to experience faults risking catastrophic mission failure creating large financial setbacks and an increased risk of human safety. Different fusion methods are analyzed for a multi-sensor network using cost effective IMUs, including direct averaging and covariance intersection. Simulations of a spacecraft in low Earth orbit are used to baseline a typical expensive IMU and compare the navigation solution obtained from a network of several …

Bayesian Inference For Dynamic Pose Estimation Using Directional Statistics, Jacob E. Darling

Doctoral Dissertations

"The dynamic pose of an object, where the object can represent a spacecraft, aircraft, or mobile robot, among other possibilities, is defined to be the position, velocity, attitude, and angular velocity of the object. A new method to perform dynamic pose estimation is developed that leverages directional statistics and operates under the Bayesian estimation framework, as opposed to the minimum mean square error (MMSE) framework that conventional methods employ. No small attitude uncertainty assumption is necessary using this method, and, therefore, a more accurate estimate of the state can be obtained when the attitude uncertainty is large.

Two new state …

Guidance And Navigation For A Spinning Projectile Using A Strapdown Seeker, Timothy J. Josey

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis describes the derivation and implementation of an Extended Kalman Filter for the purpose of estimating the line of sight rates between a non-thrusting, guided projectile and a ground target. Line of sight rates are required signals to implement the proportional navigation guidance scheme. Using low-cost strapdown sensors, the line of sight rate is not directly measurable but is observable as shown in this thesis. The line of sight signal generated by strapdown seekers inherently includes projectile body motion, but with the use of a global positioning system and a strapdown inertial sensor suite, the seeker signal is transformed …

Error Characterization Of Flight Trajectories Reconstructed Using Structure From Motion, Daniel C. Alix

Theses and Dissertations

This research effort assessed the accuracy of Structure from Motion (SFM) algorithms in replicating aircraft fight trajectories. Structure from Motion techniques can be used to estimate aircraft trajectory by determining the position and pose of an aircraft mounted camera from a sequential series of images taken during flight. An algorithm is proposed and implemented that successfully reconstructed aircraft trajectory using only a known starting position and a sequential series of images. The error in and reliability of the algorithm was found to be a function of image resolution as well as the amount of overlap and angular separation between sequential …

Navigation Constellation Design Using A Multi-Objective Genetic Algorithm, Heather C. Diniz

Theses and Dissertations

In satellite constellation design, performance and cost of the system drive the design process. The Global Positioning System (GPS) constellation is currently used to provide positioning and timing worldwide. As satellite technology has improved over the years, the cost to develop and maintain the satellites has increased. Using a constellation design tool, it is possible to analyze the tradeoffs of new navigation constellation designs (Pareto fronts) that illustrate the tradeoffs between position dilution of precision (PDOP) and system cost. This thesis utilized Satellite Tool Kit (STK) to calculate PDOP values of navigation constellations, and the Unmanned Spacecraft Cost Model (USCM) …

Modeling, Dynamics And Control Of Spacecraft Relative Motion In A Perturbed Keplerian Orbit, Mohamed Okasha, Brett Newman

Mechanical & Aerospace Engineering Faculty Publications

The dynamics of relative motion in a perturbed orbital environment are exploited based on Gauss' and Cowell's variational equations. The inertial coordinate frame and relative coordinate frame (Hill frame) are used, and a linear high fidelity model is developed to describe the relative motion. This model takes into account the primary gravitational and atmospheric drag perturbations. Then, this model is used in the design of a navigation, guidance, and control system of a chaser vehicle to approach towards and to depart from a target vehicle in proximity operations. Relative navigation uses an extended Kalman filter based on this relative model …

Vision-Aided Navigation For Gps-Denied Environments Using Landmark Feature Identification, Tennyson Samuel John

Doctoral Dissertations and Master's Theses

In recent years, unmanned autonomous vehicles have been used in diverse applications because of their multifaceted capabilities. In most cases, the navigation systems for these vehicles are dependent on Global Positioning System (GPS) technology. Many applications of interest, however, entail operations in environments in which GPS is intermittent or completely denied. These applications include operations in complex urban or indoor environments as well as missions in adversarial environments where GPS might be denied using jamming technology.

This thesis investigate the development of vision-aided navigation algorithms that utilize processed images from a monocular camera as an alternative to GPS. The vision-aided …

Joint Architecture For Reusable Vehicle-Integrated Software (J.A.R.V.I.S), Anthony Mark Kane

Open Access Theses

An integrated software architecture for development of unmanned research vehicles is developed. It has been created under the premise that all unmanned vehicles require a core set of functionality that is common across platforms and that priority should be to the readability and reusability of the code base. The architecture defines the top-level system interfaces allowing internal algorithms to be manipulated without affecting the rest of the system. A robust aerospace toolbox has been developed that provides a means to rapidly prototype algorithms without the need of recreating commonly used functions or the use of expensive, proprietary software.

Linear Covariance Analysis For Gimbaled Pointing Systems, Randall S. Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Linear covariance analysis has been utilized in a wide variety of applications. Historically, the theory has made significant contributions to navigation system design and analysis. More recently, the theory has been extended to capture the combined effect of navigation errors and closed-loop control on the performance of the system. These advancements have made possible rapid analysis and comprehensive trade studies of complicated systems ranging from autonomous rendezvous to vehicle ascent trajectory analysis. Comprehensive trade studies are also needed in the area of gimbaled pointing systems where the information needs are different from previous applications. It is therefore the objective of …

Statistical Methods For Launch Vehicle Guidance, Navigation, And Control (Gn&C) System Design And Analysis, Michael Benjamin Rose

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A new tool for launch vehicle design and analysis is developed. The tool is capable of rapid analysis of requirements tradeoffs affecting system design and developed to reduce turnaround time for launch vehicle design and mission planning. It is streamlined to quickly determine trajectory and attitude control dispersions which represent how far the actual trajectory is expected to deviate from the nominal flight path, propellant dispersions which represent how much propellant is required to meet mission requirements, and navigation errors which represent how far the navigation filter’s estimate of the actual trajectory is expected to deviate from the actual trajectory. …

Guidance, Navigation And Control Of A Fly-By-Wire Transport Category Airship Designed For Hover Cargo Delivery, Harshad H. Lalan

Master's Theses - Daytona Beach

The purpose of this thesis is to develop fly-by-wire pilot controls for a transport category airship propelled with six thrust vectoring engines, and to develop control laws to maintain position, heading, and attitude during hover and cargo operations. Owing to the large body area, most airships require that they be pointed into the wind to maintain their position. This research aims at controlling an airship attitude and position during hover cargo delivery, irrespective of the wind direction.

Control laws were developed for two primary modes of the airship: Flight (High Speed Mode) and Hover (Cargo Delivery Mode). Different sets of …

Hot Air Balloon Navigation, Dustin Blackwell

Aerospace Engineering

This report describes a program used for navigating a hot air balloon.  The program, Balloon_Trip, was written using MATLAB and gives a flight path to follow from a start position to an end position.  Balloon_Trip calculates the flight path by taking in wind conditions and then flying through these different winds so as to steer the hot air balloon.  The program calculates the flight path by taking into consideration at all times how the wind will propel the balloon while it is rising or falling in elevation.  It then takes the most direct and least complicated, if not fastest, …

An Integrity Framework For Image-Based Navigation Systems, Craig D. Larson

Theses and Dissertations

This work first examines fundamental differences between measurement models established for GPS and those of proposed image-based navigation systems. In contrast to single value per satellite GPS pseudorange measurements, image measurements are inherently angle-based and represent pixel coordinate pairs for each mapped target. Thus, in the image-based case, special consideration must be given to the units of the transformations between the states and measurements, and also to the fact that multiple rows of the observation matrix relate to particular error states. An algorithm is developed to instantiate a framework for image-based integrity analogous to that of GPS RAIM. The algorithm …

Terrain-Relative And Beacon-Relative Navigation For Lunar Powered Descent And Landing, Daniel Porter Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As NASA prepares to return humans to the moon and establish a long-term presence on the surface, technologies must be developed to access previously unvisited terrain regardless of the condition. Among these technologies is a guidance, navigation and control (GNC) system capable of safely and precisely delivering a spacecraft, whether manned or robotic, to a predetermined landing area. This thesis presents detailed research of both terrain-relative navigation using a terrain-scanning instrument and beacon-relative radiometric navigation using beacons in lunar orbit or on the surface of the moon. The models for these sensors are developed along with a baseline sensor suite …

Semi-Automated Frame Transformations Using Fft Analysis On 2-D Images, Francisco Javier Osuna

Open Access Theses & Dissertations

Cassini entered Saturn's orbit on July 1, 2004 beginning a four-year exploration of Saturn. In 2008 the mission was extended, and Cassini continues to collect and transmit images and data collected during its mission. In order to accurately interpret images, it is necessary to know the location and orientation of the camera provided the field of view when the image was collected. While the mission managers provide initial estimates of this orientation, scientific analysis requires better estimates than the initial data provided. Navigation is a process for improving the estimation of the true camera pointing vector as determined by features …

Optimization Of A Strapdown Inertial Navigation System, Mario Ruiz

Open Access Theses & Dissertations

The focus of this Thesis is to find 21 error parameters in a Strapdown Inertial Navigation System (SINS) that would minimize objective functions or error functions to increase accuracy utilizing an optimization algorithm. The algorithm used is goal attainment by Gembiki which is a multi-objective optimization algorithm proven to outperform other optimization methods in terms of efficiency and accuracy over large numbers of problems. Simulations of a noise-free SINS mounted on an aircraft were done in a stationary and on the move scenario to simulate two conditions in which alignment could become necessary. The error parameters to find were sensor …

Autonomous Controls Algorithmfor Formation Flying Of Satellites, Luis Santiago

Electronic Theses and Dissertations

This document describes the design and analysis of the Navigation, Guidance and Control System for the KnightSat project. The purpose for the project is to test and demonstrate new technologies the Air Force would be interested in for research and development. The primary mission of KnightSat is to show how a constellation of satellites can maintain relative position with each other autonomously using the Microwave Electro Thermal (MET) thruster. The secondary mission is to use multiple satellite imagery to obtain 3 dimensional stereo photographs of observable terrain. Formation flying itself has many possible uses for future applications. Selected missions that …

Design Of The Guidance, Navigation, And Control Subsystem For The Proposed Firebird Spacecraft, Erin Robinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Firebird spacecraft is a space mission to gather scientific and physical data on the effects of atmospheric deceleration, commonly called aerobraking. The objective of the Firebird mission is to measure specified aerobraking parameters over a range of reentry velocities to provide a database sufficient to construct and validate mathematical models of such aerobraking mission maneuvers. The Firebird senior design team designed the first spacecraft in the mission series to look at aerobraking at an altitude of 160 kilometers above the surface of the Earth. This paper looks specifically at the design of the subsystem that provides the guidance, navigation, …

Improved Mathematical Modeling For Gps Based Navigation, Salvatore Nardi

Theses and Dissertations

This thesis is concerned with the development of new closed form GPS position determination algorithms that work in the presence of pseudorange measurement noise. The mathematical derivation of two closed form algorithms, based on stochastic modeling and estimation techniques, is presented. The algorithms provide an estimate of the GPS solution parameters (viz., the user position and the user clock bias) as well as the estimation error covariance. The experimental results are analyzed by comparison to the baseline results from the conventional Iterative Least Squares (ILS) algorithm. In typical GPS scenarios, the closed form algorithms are extremely sensitive to noise, making …

Pseudorandom Code Generation For Communication And Navigation System Applications, John F. Brendle Jr.

Theses and Dissertations

This research project investigated the design, construction and evaluation of a pseudorandom code generator for communication and navigation system applications. These types of codes include spreading codes, Gold codes, Jet Propulsion Laboratory (JPL) ranging codes, syncopated codes, and nonlinear codes. Such waveforms are typically used in communication and navigation system applications. The code generator uses the Stanford Telecom STEL-1032 Pseudorandom Number (PRN) coder. A coder interface was designed and constructed for manual data entry to the registers of the PRN coder. The code generator is capable of independently clocking and generating all possible codes with lengths up to 4,294,967,295 bits. …

Analytical Guidance Laws And Integrated Guidance/Autopilot For Homing Missiles, S. N. Balakrishnan, Donald T. Stansbery, J. H. Evers, J. R. Cloutier

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An approach to integrated guidance/autopilot design is considered in this study. It consists of two parts: 1) recognizing the importance of polar coordinates to describe the end game in terms of problem description and measurement acquisition, the terminal guidance problem is formulated in terms of polar coordinates; 2a) through the use of the state transition matrix of the intercept dynamics, a closed form solution for the transverse command acceleration is obtained; and 2b) through a commonly used approximation on time-to-go and a coordinate transformation, a family of proportional navigation optimal guidance laws is obtained in a closed form. A typical …